Carbon pile regulator



mm m 1935, A BROWN 2,023,723

CARBON FILE REGULATOR Filed Oct. 12, 1934 GVLMMWJ aw Patented Dec. 10, 1935 UNITED STATES PATENT OFFICE CARBON FILE REGULATOR Britain Application October 12, 1934, Serial No. 748,128 In Great Britain November 3, 1933 7 Claims.

This invention concerns improvements relating to adjustment and re-adjustrnent, or resetting, means for electro-magnetic carbon pile regulators of the type wherein the compression of a carbon pile is varied under the control of the armature of an electro-magnet which is opposed by a spring system matched therewith. Regulators to which the present improvements are particularly applicable are described in the specifications of patent application of Alfred H. Chilton, Serial No. 683,557, filed August 3, 1933, and United States Patent to Alfred H. Chilton, No. 1,963,825, dated June 19, 1934. In such regulators, for example, the original setting is liable to become deranged or inaccurate in the course of time owing to changes in the components of the regulator. More especially is the carbon pile itself liable to such a change, its overall length being gradually reduced by the wear due to friction and the continual compression and decompression of the pile. Since, however, the distance between the two anchorage or abutment points of the pile does not decrease similarly, the compression in the pile gradually decreases and its resistance increases from the original calibration. In particular the initial compression in and resistance of the pile may be appreciably affected.

It is one object of the present improvements to provide a simple and reliable resetting or adjustment device whereby the force in the carbon pile can be adjusted or reset to substantially an original value without the necessity for energizing such apparatus or for employing electrical instruments, external counter-balancing means or the like, and also without expert assistance or the removal of the regulator from service.

With this object in view, resetting or adjustment means according to the present improve-- ments comprises an elastic member, such as a spring, adapted for exerting a substantially constant force upon an anchorage or abutment of the carbon pile, and a releasable locking device for the anchorage or abutment. Means, preferably adjustable, are provided for stressing the elastic member to exert a predetermined force, the elastic member being adapted for maintaining substantially that force upon the anchorage or abutment in spite of small alterations of position of the latter. It follows that release of the anchorage or abutment by the locking means, in the initial position of the apparatus, permits the force of the elastic member to be exerted upon the carbon pile, re-establishing in the same the predetermined initial force originally obtaining therein. The anchorage or abutment, which may move slightly, is then looked in position, leaving the carbon pile subject to the predetermined initial force. 4

A further object of these improvements is to provide means for adjusting the rate of the 5 spring of the main spring system of a regulator of the type set forth. For this purpose an anchorage for the spring is provided with an external thread upon which said spring can be screwed like a nut. Preferably, a skirted locking sleeve is also screwed upon the anchorage to engage against the end of the spring and, with its skirt, to embrace the part of said spring which is screwed upon said anchorage.

One embodiment of these improvements by way of example will now be described with reference to the accompanying drawing, in Which:

Figure 1 is a rear elevation of a regulator, and

Figure 2 is a vertical section of the upper part thereof.

The regulator illustrated has matched magnet and spring systems essentially similar to those of the dynamo and lamp-Voltage regulators described in the specification of Patent No. 1,963,825. The present improvements, however, are equally applicable to other varieties of such carbon pile regulators. Rotatable with the rotor I of the magnet system shown is a crank I1 acting through a push-rod I9 and compression plate 20 upon the carbon pile 2|. A plate 22 at the upper end of the pile has an upward extension 23 connected by a pivot 24 to an upper abutment or anchorage 25. This takes the form of a plunger which is slidably mounted in a vertical bore 26 in the upper part of the regulator frame and at its upper end is acted upon by a heiical compression spring 21 also disposed in the said bore. The upper end of the spring takes against a plug 28 screwed into the upper end of the bore, the adjacent faces of the plunger and plug preferably having stub projections 29 which assist in locating the spring properly.

The plunger 25 has a diametrical slot I26 extending for a part of its length and through this slot is passed a locking bolt I21. The head of the bolt, accommodated in a recess I28 in the frame bears upon the plunger, whilst the stem of the bolt, after passing freely through the plunger and a bore in the frame, carries a locknut I29. The latter is preferably a hexagon nut sunk into the frame I to avoid unauthorized interference, but may be a simple knurled nut.

Also rotatable with the rotor I is a disc I6 to which a helical tension spring 32 is connected by a flexible tape 33. At its upper end, the spring 32 is connected to-an anchorage 35 pivoted to a bracket I35 which is mounted in a vertically adjustable manner upon the frame l. The lower end of this anchorage 35 has a thread of such size and pitch that the end of the spring 32 can be screwed thereon. Also screwed upon the anchorage is a locking sleeve with a shoulder 53% which can be brought into engagement with the end of the spring and a skirt lSl which then embraces the part of said spring which is screwed on the anchorage. The sleeve itself is locked by a nut When the regulator is being calibrated in the first instance, which is effected with the regulator unexcited and the mechanism in the initial condition, the nut I29 is loosened and the plug 28 screwed in or out until the requisite pressure, giving the required minimum resistance, is communicated to the pile 25 by way of the spring 2? and abutment plunger 25. The nut I29 is then tightened to lock the plunger in its adjusted position, so that the spring ceases to have any eiTect on the pile and the upper abutment of the pile remains stationary in the usual manner.

As the carbon elements of the pile wear in service, reducing the length of the pile and the pressure therein, all that need be done from time to time is to loosen the nut l 29 on the locking bolt 521. This immediately permits the spring 2'! to exert substantially the original pressure upon the pile 21, which consequently has substantially the same minimum or initial resistance as in the first instance. The nut 529 is then tightened up and the regulator, thus recalibrated, is ready for operation. The movement of the plunger 25 and elongation of the spring 2'5 upon the release of the locking bolt E27, being slight in relation to the length of the spring, are not sufficient to affect materially the compression in the spring.

The bracket E35 provides a simple tensionadjustment for the main spring 312. Since, however, it is diificult commercially to obtain springs of precisely the same rate, the anchorage means I36l38 are devised, as shown, to permit also of a simple rate-adjustment. The rate of the spring 32 can be adjusted by varying the number of coils which are rendered inoperative by being screwed on the anchorage S5. The setting is locked by screwing the sleeve I36, it! hard down on the spring, its skirt then also preventing any tendency for the spring coils to jump off the anchorage. The sleeve I35, l3? also provides a convenient means for unscrewing the spring when necessary.

With the settin arrangements described, it is possible to obtain and maintain precision of operation of the regulator for long periods without the necessity for expert maintenance, complicated testing processes, or the removal of the regulator from service.

We claim:

1. Electro-magnetic regulator, comprising a carbon pile, an abutment for said pile, an electromagnet with a rockable rotor operative for controlling the compression of said pile against, said abutment, a helical spring connected to and opposing the attraction of the rotor by the electromagnet, adjustment means operative upon the abutment for setting the initial compression in the pile to a predetermined value, and adjustment means for setting the rate of the helical spring.

2. For a carbon pile regulator, a pile assembly comprising a carbon pile, an abutment for said pile, pile-compressing means, and compressionresetting means for the carbon pile consisting of an elastic member, adapted for exerting a substantially constant force upon the abutment, and a releasable locking device for said abutment, which device, when released, permits said force to be transmitted to said pile.

3. For a carbon pile regulator, a pile assembly comprising a carbon pile, an abutment for said pile, pile-compressing means, and compressionresetting means for the carbon pile consisting of an elastic member, adapted for exerting a substantially constant force upon the abutment, adjustment means acting upon said elastic member for setting the substantially constant force to be exerted, and a releasable locking device for said abutment, which device, when released, permits said force to be transmitted to said pile.

4. In a carbon pile regulator, a pile assembly comprising a carbon pile, an abutment for said pile in the form oi a plunger, a guide in the regulater for said plunger, pile compressing means, and compression-resetting means for the pile consisting of a helical compression spring disposed in said guide and operative upon said plunger with a substantially constant force, and a releasable locking device for said plunger, which device, when released, permits said force be transmitted to said pile.

5. In a carbon pile regulator, a pile assembly comprising a pile, means for compressing said pile, an abutment for said pile in the form of a slotted plunger, a guide the regulator for said plunger, a bolt for locking said plunger in the guide, said bolt having a stem passing through the slot in the plunger and a head which bears on said plunger, and an elastic member disposed in the guide and acting upon the plunger with a substantially constant force.

6. Carbon pile regulator comprising a magnet system with a rocking rotor, an opposing spring system matched with said magnet system and comprising a helical spring and means for setting the rate of said spring consisting of an anchorage with an external thread upon which said spring can be screwed like a nut.

'7. Carbon pile regulator comprising a magnet system with a rocking rotor, an opposing spring system matched with said magnet system and comprising a helical spring and means for setting the rate or" said spring consisting of an anchorage with an external thread upon which said spring can be screwed like a nut, and a skirted sleeve adapted for being screwed upon the anchorage to engage against the end of the spring and, with its skirt, to embrace that part of the spring which is screwed upon said anchorage.

A. J. S. BROWN.

A. L. ASH. 

